tramsey

Need some help with a poor idling issue. I have a 87 911 that was stored over the winter with Sta-bil. I took the car out about 6 weeks ago with no issues. The car ran fine and was idling perfectly. I went to drive it yesterday and it sputtered when starting and backfired. It started up but will not idle. Once started, if I keep the revs up it runs fine, but stutters and spits if I let it go to idle position. I checked the idle control valve, idle position switch, vacuum lines, etc. but everything seems to be ok as far as voltage and resistance values listed in the service manual. It feels more like the injectors are blowing too much fuel and it is flooding itself. Any ideas?

Amber Gramps

It always seems to be the ICV or a vacuum leak.

ICV is a simple swap for a known good or new.

Vacuum leak for me is a can of brake-kleen on the suspected locations.

Anyway, welcome to Rennlist. Post pictures ASAP

tramsey

Thanks Amber Lamps. I've got the brake-Kleenex in my hand. I've checked the usual suspects.bill keep digging.

Ed Hughes

I'm wondering if you have moisture in your ignition somehow? May be worth pulling wires, cap, rotor to peek.

Amber Gramps

Following Ed's advice is usually a good place to start.

I remember giving mine it's first bath and not being able to fire it up afterwards. New distributor cap and rotor and I was off to the races.

tramsey

Thanks guys, I been running down things and found the problem. When it backfired it partially blew off the 90 elbow coming off of the AFM. It wasn't obvious and I couldn't see it, until I kept feeling around and found it. Whew. Running great now.

theiceman

yeah big *** vacuum leak will do it .

dshepp806

tramsey,

Have you a pic of this failed area?

Thanks,

Doyle

Ed Hughes

I'd still check ignition. Backfiring on a DME motor doesn't just happen. My guess is water was involved. Your problem sure seems succinct, and I can see it happening, but why did it backfire to begin with?

Amber Gramps

Are you thinking that the backfire preceded and caused the hose coming off? I was thinking the hose worked it's self loose and that caused the backfire. Once the hose is back on, no more backfiring.

I seem to remember, once upon a time, putting my intake back on and forgetting that very same hose. It ran, but ran like crap and would not idle.

Anyway,

Ed Hughes

That's a theory too-could be the culprit. I once was driving to a DE, and pulled out of a gas station in pouring rain. A huge stream of water hit my new Clewitt wires and killed the car. After some fidgeting, I got it to fire, with a huge backfire that blew out a couple of exhaust gaskets.